there are various versions of 'Lord Randall'..in most, it seems to be his own sweetheart/lover/girlfriend, but in some versions there seems to be an implication that his own mother, or his girlfriends mother does it...the origins of the story/ballad are lost in history. It has been seen in Italian, German, Swedish,etc.versions, as well as the English/Scottish versions set out in F.J. Child.The basic story is just that there was a young man who went out one day, had supper away from home, and was poisioned by someone he trusted. He is sometimes called 'Lord Ronald", and other names....You will probably get several answers to this...Lord Randal is one of the best known of the 'Child Ballads', and has a number of very fine and different tunes associated with it.